This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. HIV infection can pass from mother to baby while she is pregnant or while she is delivering. This is called perinatal HIV transmission. Doctors and nurses give HIV infection, special medicines called antiretroviral (anti-HIV) drugs to help prevent perinatal HIV transmission. Babies are exposed to these drugs before they are born. Babies are also given antiretrovirals to prevent HIV infection. Now 97 babies out of 100 are free of HIV.